Ouka
Ouka is a striking ornamental medaka that combines a vivid orange-to-red body with a metallic body-light sheen running along its back. The interplay of color and shine makes it equally attractive viewed from above or from the side, so its look shifts pleasantly with the angle and the light. Reaching about 3 to 4 cm as an adult, Ouka stays compact and easy to house in a tank or outdoor container. It is generally considered a variety for keepers who already have some medaka-keeping experience, making it a rewarding next choice once the basics feel comfortable. With the calm temperament typical of medaka, it tends to get along well alongside others.
View Ouka encyclopedia →0% commission on your first sales!Register by September 30, 2026 and your first 2 sales are commission-free!
Breeder Wanted!
List on BreederDirect and sell directly to customers nationwide!
9 Transparency Commitments from Br-Choku
Each Medaka listing includes the following from Breeder. Full transparency on color variations (Yokihi/Miyuki/Lame) and lineage guaranteed.
- Variety Name
- Lineage
- Actual Photos
- Color Classification
- Body Type
- Scale Type
- Size
- Origin
- Age/Generation
Browse all 116 breeds
Color
Scale Type
Verified breeders wanted for Medaka
Breeders are signing up now ahead of launch. Subscribe to be notified when new listings go live.
Getting alerts is free with a member account. When new listings match your saved search, we'll notify you by email and in-app.
Browse other categories
Verified breeders (preview)
Ouka key facts
- Care level
- Intermediate
- Lifespan
- 2-3 years
- Size
- 3-4cm
- Temperature
- 5〜30℃
- Diet
- Medaka pellets, daphnia
- Container
- White container highlights contrast of external light and red body
- Lighting
- Kept outdoors in sunlight the red body deepens further, and the body light shines brighter in the sun.
- Water Temperature & Quality
- Tolerates 5-30°C with 20-28°C ideal. Adapts to neutral to slightly alkaline water and is easy to keep.
- Diet & Feeding
- Feed medaka pellets as the staple with daphnia. Color-enhancing feed with carotenoids or astaxanthin maintains and improves the red.
- Breeding
- Select and breed individuals with strongest external body light
About Ouka
Ouka is an ornamental medaka with a rich orange-red body and shimmering body light along its back, striking from both above and the side. It suits intermediate keepers, reaches about 3-4 cm as an adult, and typically lives 2-3 years.
7 things to know before welcoming a Ouka
1Watch the Body Light Develop
Ouka's signature feature is the metallic body-light sheen along its back paired with an orange-red body color. How this shimmer develops can shift subtly with growth stage and everyday conditions, which is part of the enjoyment of keeping this variety.
2Beautiful From Above or the Side
The color and body-light pattern are bred to look attractive both from a top-down view and a side view through the glass. You can choose the viewing style that best suits your container and layout.
3Best Suited to Intermediate Keepers
Ouka is generally considered a variety for intermediate-level keepers. Coming to it after some prior medaka-keeping experience makes it easier to consistently bring out its color and shimmer.
4Expect a 2-3 Year Lifespan
Ouka typically lives around 2 to 3 years. Since this means a multi-year commitment, it helps to set up a water-change and seasonal-care routine you can sustain comfortably.
5Adults Reach About 3-4 cm
As adults, Ouka typically reach roughly 3 to 4 cm in length. When choosing a tank or outdoor container, factor in this adult size along with how many fish you plan to keep together.
6Watch Water Quality and Temperature
Because it is rated for intermediate keepers, Ouka can be sensitive to sudden shifts in water quality or temperature. Regular water changes and checking temperature at seasonal transitions help keep conditions stable.
7Prepare the Setup Before Arrival
Before bringing Ouka home, it helps to have your tank or outdoor container, filter, and substrate ready in advance. Acclimating them slowly to the new water reduces stress during the transition.
Frequently asked questions about Ouka
- Q.How difficult is it to keep Ouka?
- A.Ouka is generally considered suited to intermediate keepers. Some prior experience with basic medaka care makes it easier to consistently bring out its color and body light.
- Q.How large does Ouka grow?
- A.As an adult, Ouka typically reaches about 3 to 4 cm in length. Keep this adult size in mind when choosing a tank or container.
- Q.How long do Ouka typically live?
- A.Their typical lifespan is around 2 to 3 years. Keeping water quality and temperature stable is a key part of supporting a healthy, comfortable life.
- Q.Can Ouka be kept together with other medaka?
- A.Ouka is commonly kept alongside other medaka varieties. If there is a noticeable size difference between fish, it is worth watching how feeding and compatibility play out and adjusting as needed.
- Q.Does the body light change as Ouka grows?
- A.The body light's appearance can shift gradually depending on the individual fish and its environment. Watching these changes over time is part of the appeal of keeping Ouka.
Useful tools for Ouka care
Learn more about Ouka in the encyclopedia
View Ouka encyclopedia entry →
Care difficulty, lifespan, size and diet — all basics covered.
More in this category
Can't find the one you're looking for?
Post your wishes for free and breeders with matching animals will contact you with introductions.